Objective To systematically evaluate the associations between SEC16B polymorphisms and body mass index (BMI) or risk of obesity in different ethnic populations.Methods A literature retrieval was carried out by using Wanfangdata,Chinese National Knowledge Infrastructure (CNKI),China Science and Technology Journal Database (VIP databases),PubMed,Embase,Web of Science,NIH GWAS catalog databases to collect the research papers published between 2009 and 2015 on the associations between SEC16B polymorphisms and BMI or risk of obesity.Summary beta estimates (βs),odds ratios (ORs) and 95％ confidence intervals (CIs) were calculated to assess the strength for the BMI analyses and obesity status.Meta-analysis was performed with Stata 12.0 software.Results Totally 15 papers for rs10913469 and 13 papers for rs543874 were included in this Meta-analysis.Under additive genetic model,rs10913469 and rs543874 in SEC16B gene were positively associated with BMI,and the combined β was 0.04 (95％CI:0.03-0.05) and 0.03 (95％CI:0.02-0.04),respectively,and rs10913469 and rs543874 were also associated with the risk of obesity,and the combined OR was 1.11 (95％CI:1.08-1.15) and 1.28 (95％CI:1.20-1.36),respectively.There were no significant differences among subgroups of ethnicity,different age groups and literatures with different quality.Conclusion rs10913469 and rs543874 in SEC16B gene are significantly associated with BMI and the risk of obesity,and C allele ofrs10913469 and G allele ofrs543874 increase the risk for obesity in different ethnic populations.

Objective To investigate possible effect of 6 obesity-associated SNPs in contribution to central obesity and examine whether there is an interaction in the 6 SNPs in the cause of central obesity in school-aged children in China.Methods A total of 3502 school-aged children who were included in Beijing Child and Adolescent Metabolic Syndrome (BCAMS) Study were selected,and based on the age and sex specific waist circumference (WC) standards in the BCAMS study,1196 central obese cases and 2306 controls were identified.Genomic DNA was extracted from peripheral blood white cells using the salt fractionation method.A total of 6 single nucleotide polymorphisms (FTO rs9939609,MC4R rs17782313,BDNF rs6265,PCSK1 rs6235,SH2B1 rs4788102,and CSK rs1378942) were genotyped by TaqMan allelic discrimination assays with the GeneAmp 7900 sequence detection system (Applied Biosystems,Foster City,CA,USA).Logistic regression model was used to investigate the association between 6 SNPs and central obesity.Gene-gene interactions among 6 polymorphic loci were analyzed by using the Generalized Multifactor Dimensionality Reduction (GMDR) method,and then logistic regression model was constructed to confirm the best combination of loci identified in the GMDR.Results After adjusting gender,age,Tanner stage,physical activity and family history of obesity,the FTO rs9939609-A,MC4Rrs 17782313-C and BDNF rs6265-G alleles were associated with central obesity under additive genetic model (OR=1.24,95％CI:1.06-1.45,P=0.008;OR=1.26,95％CI:1.11-1.43,P=2.98 × 10-4;OR=1.18,95％ CI:1.06-1.32,P=0.003).GMDR analysis showed a significant gene-gene interaction between MC4R rs17782313 and BDNF rs6265 (P=0.001).The best two-locus combination showed the cross-validation consistency of 10/10 and testing accuracy of 0.539.This interaction showed the maximum consistency and minimum prediction error among all gene-gene interaction models evaluated.Moreover,the combination of MC4R rs17782313-C and BDNF rs6265-G was associated with an increased risk of central obesity after adjustment for gender,age,Tanner stage,physical activity and family history of obesity.Conclusions Our study showed that FTO rs9939609-A,MC4R rs17782313-C and BDNF rs6265-G alleles were associated with central obesity,and statistical interaction between MC4R rs17782313-C and BDNF rs6265-G increased risk of central obesity in school-aged children in China.

Objectives:Compare the differences between the intervention and control groups in changes of primary outcomes(body mass index[BMI]and waist-to-height ratio[WHtR])and secondary outcomes(nutrition knowledge of children and parents),from baseline to the 6-and 12-month follow-ups;examine the associations of changes in nutrition knowledge of children and their parents with children's changes in BMI and WHtR.Data sources:Data collected from four schools in two poverty-stricken counties in northern Shaanxi Province in 2020-2021.Methods:A multifaced intervention program targeted children(promoting healthy diet and nutrition education)and their parents(promoting nutrition knowledge)was conducted in the interventional group.Four schools,with two in each group,were randomly allocated to the intervention or control group,with 814 eligible children aged 7.1 to 12.8 years.The control group conducted myopia promotion.Differences in changes of BMI and WHtR between groups were compared with t-test.Mixed-effects model was used to examine the associations between changes in nutrition knowledge of children and parents with changes in children's BMI and WHtR.Results:At the 6-month follow-up,the difference in changes in BMI between the intervention and control groups was 0.4 kg/m 2(P＜0.001).At the 12-month follow-up,the difference in changes in BMI and WHtR between intervention and control groups was 0.1 kg/m2(P＜0.001)and 0.01 kg/m2(P＜0.001).In the intervention group,the nutrition knowledge awareness rate of children increased from 16.9％(69/409)at baseline to 21.3％(87/409)at 6-month,and 22.7％(93/409)at 12-month.The awareness rate of nutrition knowledge of parents also fluctuated,from 5.6％(23/409)to 6.6％(27/409)and 5.4％(22/409).However,the difference in changes in nu-trition knowledge between intervention and control groups was non-significant.The 6-month follow-up changes in children's nutrition knowledge scores were negatively associated with changes in BMI in girls(β=-0.26,95％confidence interval[CI]:-0.38 to-0.14,P＜0.001),while positively associated with changes in WHtR in boys(β=0.003,95％CI:-0.0002 to 0.005,P=0.035).The 12-month follow-up changes in children's nutrition knowledge scores were positively associated with changes in children's WHtR(β=0.003,95％CI:0.0004 to 0.01,P=0.018).Conclusions:The intervention strategies did not reduce the BMI and WHtR of children,and the nutrition knowl-edge of children and parents increased after the intervention in intervention group.Changes in nutrition knowl-edge of children and their parents are associated with changes in children's BMI or WHtR.Interventions with a new focus on obesity are needed to help improve children's nutritional status in poverty-stricken areas in Shaanxi Province of China.

Objective: To investigate the status of nutrition and dietary behaviors and their associations in school age children in poor areas of western China, to provide clues for sustainable improvement strategies of malnutrition among primary school students in rural revitalization. Methods: A total of 1 887 school age students from 3 poverty stricken counties in Shaanxi and Sichuan provinces were investigated by physical examination and questionnaire survey during October to December in 2020. Mixed effects model was used to analyze associations between nutritional status and dietary behaviors. Results: The prevalence of stunting, wasting, overweight and obesity, and central obesity among 1 887 students were 1.8%, 6.6%, 27.7%, 24.5%, respectively, and the differences between two provinces were statistically significant ( χ 2=94.76, 46.05, 109.96, 80.50, P <0.05). The prevalence of overweight and obesity of students in Shaanxi and Sichuan were 32.8% and 4.9%, respectively. The prevalence of stunting and wasting were 0.4% and 4.7% in Shaanxi, and 8.1% and 14.7% in Sichuan, respectively. Among 1 160 students with complete dietary data, the proportions of students who ate breakfast, eggs, and milk daily were low, and eating breakfast daily was negatively associated with overweight and obesity( OR =0.26, P <0.05), and eating out and eating in canteen were positively associated with wasting( OR = 2.51, 2.82, P <0.05). Conclusion School age children in poor areas of western China are facing double burden of malnutrition, and there are significant regional differences. Future targeted interventions should be made to improve these students nutritional status.

Objective:Socioeconomic status(SES)is associated with childhood obesity,but the underlying factors remain unknown.This study aimed to identify mediators that may explain SES disparities in childhood obesity in China.Methods:Nationally representative longitudinal data from the China Education Panel Survey of 11 019 chil-dren(13.03±0.79)collected from 2013-2014 to 2016-2017 academic years.Overweight/obesity was de-fined using Chinese national body mass index cut-points.Principal component analysis was used to con-vert the four SES indicators(maternal and paternal education,and occupation)into one comprehensive vari-able.Mediation analysis for SES disparities in childhood obesity was conducted using structure equation models.Results:The prevalence of overweight/obesity was 12.8％,and was higher in boys than in girls(17.8％vs.7.6％,P＜0.001)at baseline.Among boys,relative risk(RR)of obesity was 1.23(95％CI:1.09 to 1.40,P＜0.001)for per unit change in SES.There was no significant association between obesity and SES among girls.Mediation analyses showed that among boys,birth weight,being the only child in the family and children's self-perceived weight status mediated 70.0％of the effects of SES on obesity.No mediation effect was detected in girls.Conclusions:Chinese boys are more likely to be overweight or obese than girls.SES may impact childhood obesity through birth weight,being the only child in the family and children's self-perceived body weight status in boys,but not in girls.More attention should be made to address childhood obesity in high SES families among boys.Interventions targeting at these mediators are needed.

Objective:Examine effect of sleep duration on children's risk of overweight and obesity;and study associations between activities in the last hour before bedtime and sleep outcomes(sleep duration,sleep quality,and sleep onset latency).Methods:Children's data were recruited using a questionnaire survey from a nationally representative sample of children(n=10 279)in China in 2013-2016.Mixed-effects models were used to test associations among variables stratified by sex.Results:Sleep duration was positively associated with BMI in boys(p=0.04,P=0.021).Girls with short sleep durations(＜8 h/d)tended to have higher BMI values than those with normal sleep durations(8-9 h/d)(β=0.12,P=0.063).The top three activities were playing electronic devices(Factor 1),doing homework,and reading(combined as Factor 2).Factors 1 and 2 were both significantly associated with sleep duration(β=0.17,P＜0.001;β=-0.26,P＜0.001,respectively).Conclusion:Sleep duration seems to affect BMI in Chinese children.Using electronic devices and reading before bedtime influenced sleep duration.Good bedtime habits and sleep duration can help weight management in children.